JP4708202B2 - Battery and battery manufacturing method - Google Patents

Description

  The present invention relates to a battery and a battery manufacturing method.

As shown in FIG. 11, as a conventional battery B, a positive electrode plate 71 and a negative electrode plate 72 are spirally wound through a separator 73, and the wound electrode group 74 is accommodated in a case 75 and sealed. There is a structure closed at 76. By the way, the electrode group 74 is accommodated in the case 75 via the current collector 77 and is closed by the sealing plate 76. When the sealing plate 76 is attached, the filter 79 connected to the cap-like positive electrode terminal 78 and A tab 80 is provided between the current collector 77 to electrically connect them. The tab 80 is formed in an S-shaped cross section, and elastically absorbs a dimensional error in the vertical direction of the electrode group 74 (see Patent Document 1).
JP-A-10-106533

However, although the conventional battery B is excellent in that the dimensional variation of the electrode group 74 can be absorbed by the tab 80, the height dimension increases by the amount of the tab 80. When used in series, there is a problem that the occupied space of the battery B increased by the tab 80 cannot be ignored.
Further, there is a problem that the internal resistance of the battery B is increased by the provision of the tab 80, which hinders high output.

  Therefore, an object of the present invention is to provide a battery and a battery manufacturing method that can absorb the dimensional variation of the electrode group without using a tab and can avoid an increase in internal resistance.

In order to achieve the above object, the invention described in claim 1, a strip-like positive electrode plate (for example, positive electrode plate 34 in the embodiment) and a negative electrode plate (for example, negative electrode plate 35 in the embodiment) are separated from each other (for example, The electrode group (for example, the electrode group 37 in the embodiment) insulated by the separator 36) in the embodiment and wound in a spiral shape is housed in a bottomed cylindrical case (for example, the case 31 in the embodiment). In the battery in which the opening (for example, the upper opening 32 in the embodiment) is closed by a sealing plate (for example, the sealing plate 33 in the embodiment) via a sealing member (for example, the gasket 50 in the embodiment), the sealing plate A vertical wall portion (for example, a vertical wall in the embodiment) that rises in the direction along the outer wall surface of the case (for example, the outer wall surface 55 in the embodiment) at the periphery of the case 56), the vertical wall portion and the peripheral edge of the opening of the case (for example, the peripheral edge 49 of the opening in the embodiment) are overlapped, and either the peripheral edge of the opening of the case or the vertical wall of the sealing plate one folded lower after involving relative to the other to, characterized in that fixing the sealing plate to the case by caulking with. As in the invention described in claim 2, the terminal of the vertical wall portion of the sealing plate (for example, the terminal 57 in the embodiment) is bent outward and then bent downward, so that the periphery of the opening of the case is wound. Or by folding the peripheral edge of the opening of the case inward and then bending downward , as in the invention described in claim 3, and fixing the vertical wall portion of the sealing plate so as to be wound. Can do.
By configuring in this way, the dimensional variation in the height direction of the electrode group is changed in the vertical direction of the case by changing the overlapping position of the vertical wall portion of the overlapped sealing plate and the periphery of the opening portion of the case. Adjust the position and absorb.

The invention described in claim 4 is characterized in that it is used as a power source for driving a motor of a vehicle (for example, the vehicle 1 in the embodiment) provided with a driving motor or a driving assist motor.
With this configuration, when a plurality are connected in series, the occupied space can be greatly reduced, and the internal resistance can be reduced as compared with the case where a tab is used.

According to a fifth aspect of the present invention, an electrode group in which a strip-like positive electrode plate and a negative electrode plate are insulated with a separator and wound in a spiral shape is housed in a bottomed cylindrical case, and the opening of the case is sealed. A method for manufacturing a battery closed by a sealing plate through a member, the step of welding the electrode group and the current collector (for example, the second step in the embodiment), and the case from the opening of the case A step (for example, a third step in the embodiment) of housing a sealing plate having a peripheral wall with a vertical wall that rises in a direction along the outer side surface of the case, any of the peripheral edge of the opening of the case and the sealing plate step (e.g., the fifth step in the embodiment) for fixing said sealing plate to said casing caulked by bending the lower or one after involving relative to the other and having a.

According to the invention described in the first to third aspects, by changing the superposition position of the vertical wall portion of the superposed sealing plate and the periphery of the opening portion of the case, the dimensional variation in the height direction of the electrode group, Since the position can be adjusted and absorbed in the longitudinal direction of the case, there is no need for a tab, and an increase in internal resistance can be prevented and the number of parts can be reduced.
According to the invention described in claim 4 , when a plurality are connected in series, the occupied space can be greatly reduced and the internal resistance can be reduced as compared with the case where a tab is used. There is an effect that can generate.
According to the invention described in claim 5, when the sealing plate having the vertical wall portion is accommodated from the opening portion of the case, the sealing plate is inserted into the case up to a position corresponding to the height dimension of the electrode group. Since the case and the sealing plate are fixed, there is no need for a special positioning step of the sealing plate with respect to the case, and there is an effect that the number of work steps can be reduced as compared with the case where a tab or the like is used.

Next, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show that a plurality of batteries according to an embodiment of the present invention are connected in series and mounted on a hybrid vehicle as a battery unit. The battery unit is a motor for driving driving assistance or for decelerating regeneration. Used as a chargeable / dischargeable power source.

  As shown in FIGS. 1 and 2, a power unit 3 having a motor sandwiched between an engine and a transmission is mounted in an engine room 2 at the front of the vehicle body of the vehicle 1. Is transmitted to the front wheel 4. A front seat 5 and a rear seat 6 are disposed in the vehicle compartment 7 at the rear of the engine room 2, behind the seat back 6 a of the rear seat 6 in the trunk room 8, the lower part in the rear cross member 9, and the upper part in the rear parcel 10. The high-voltage equipment boxes 11 fixed to each other are arranged.

  The high piezoelectric equipment box 11 is connected to the power unit 3 via the power cable 13 below the floor 12, and the battery unit 15 is accommodated in the outer case 14 of the high piezoelectric equipment box 11 as shown in FIGS. 2 and 3. The battery box 16 and the inverter unit 17 are arranged separately on the left and right. In FIG. 3, reference numeral 18 denotes an intake duct that can introduce the air in the passenger compartment 7, 19 denotes an exhaust duct, and 20 denotes a cooling fan.

  As shown in FIG. 4, the battery box 16 includes a box body 21, a lid portion 22, and a side plate 30. The battery box 16 accommodates the battery unit 15 that is restrained by the upper holder 23, the middle holder 24, and the lower holder 25 and that is held by the holding frame 26. In the battery unit 15, a plurality of rod-shaped batteries 27 in which six batteries B are connected in series are arranged in a plurality of rows, and each rod-shaped battery 27 is connected in series by a joint 28. It is what was done. Reference numeral 29 denotes a bus bar plate.

FIG. 5 is a cross-sectional view of the battery, and FIG. 6 is an exploded perspective view of the battery. As shown in the figure, this battery B is a chargeable / dischargeable secondary battery such as an alkaline livestock battery, a nickel metal hydride battery, a lithium ion battery, etc., and a case 31 that is made of a bottomed cylindrical metal and constitutes a negative electrode. A sealing plate 33 attached to the upper opening 32 of the case 31 is provided.
In the case 31, an electrode group 37 is housed together with an electrolytic solution, in which a strip-like positive electrode plate 34 and a negative electrode plate 35 are insulated by a separator 36 and wound in a spiral shape. The positive electrode plate 35 protrudes upward, and the negative electrode plate 35 protrudes downward. A negative electrode current collector 38 is disposed below the electrode group 37, and the negative electrode current collector 38 is interposed between the bottom wall (bottom part) 39 of the case 31.

  The negative electrode current collector 38 is a plate-like member formed in a square shape, and two pairs of slits 40, 40 ′ having different lengths from the corner portion toward the central portion are formed at intervals of 90 °. Burling protrusions 42 are cut and raised upwards from the side edges of the slits 40, 40 'on the four tongue pieces 41 defined by the slits 40, 40'. A protruding piece 43 extends outward from the outer edge of the tongue piece 41 on one side, and the tongue piece 41 is joined to the bottom wall 39 of the case 31 by resistance welding. The burring protrusions 42 are joined to the negative electrode plate 35 by resistance welding in a state where the burring protrusions 42 are cut into the lower end portion of the negative electrode plate 35 of the electrode group 37 so that the negative electrode plate 35 and the case 31 are electrically connected. .

  A positive electrode current collector 44 is placed on the electrode group 37. The positive electrode current collector 44 has a hole 45 in the central portion, and is a plate-like member formed in a square shape like the negative electrode current collector 38, and has a 90 ° degree interval from the corner portion to the central portion. Four slits 46 are formed. Burring projections 48 are cut and raised downward from the side edges of the slits 46 in the four tongue pieces 47 defined by these slits 46, and the tongue pieces 47 are formed on the sealing plate 33 positioned above the electrode group 37. They are joined by resistance welding. The burring protrusion 48 is joined to the positive electrode plate 34 by resistance welding with the upper end of the positive electrode plate 34 of the electrode group 37, and the positive electrode plate 34 and the sealing plate 33 are electrically connected. Yes.

  As shown in FIG. 7, a gasket (seal member) 50 having a U-shaped cross section made of nylon or the like is attached to the opening peripheral edge 49 of the case 31 so as to wrap it. The lower edge of the inner peripheral wall 51 of the gasket 50 has such a length dimension that it is positioned below the upper end of the electrode group 37 even when the electrode group 37 is positioned on the lowermost side due to dimensional variations in the vertical direction. Is formed. Further, the outer peripheral wall 52 of the gasket 50 is formed to have a dimension A longer than the caulking allowance a of the sealing plate 33.

The sealing plate 33 has a function as a noise blocking filter, and covers the upper surface of the positive electrode current collector 44 and closes the upper opening 32 of the case 31. A work hole 53 is formed in the central portion of the sealing plate 33. Further, an elastic ring portion 54 having a convex cross section concentrically downward is formed on the outer side of the sealing plate 33, and a vertical wall rising in a direction along the outer wall surface 55 of the case 31 on the outer peripheral edge of the sealing plate 33. A portion 56 is formed.
Then, the vertical wall 56 and the peripheral edge 49 of the opening of the case 31 are overlapped over the gasket 50 attached to the peripheral edge 49 of the opening, and the terminal 57 of the vertical wall 56 of the sealing plate 33 is folded outward. A sealing plate 33 is caulked and fixed to the case 31 by winding the peripheral edge 49 of the opening of the case 31 so as to sandwich the bent gasket 50 on the side.
The overlapping portion Z between the vertical wall portion 56 of the sealing plate 33 and the opening peripheral edge 49 of the case 31 is configured as a position adjusting portion with respect to the vertical (vertical) direction of the case 31.

A rubber valve body 58 is attached to the central portion of the sealing plate 33 for degassing when the internal pressure increases, and a cap 59 constituting a hat-shaped cross-sectional positive electrode is formed so as to cover the rubber valve body 58. The flange part 60 is welded and attached to the sealing plate 33.
A cylindrical joining holder 62 having a hole 61 for escaping the cap 59 is attached to the sealing plate 33, and an opening peripheral edge 63 of the joining holder 62 is stepped along the caulking portion 64 of the sealing plate 33, and is connected in series. The opening 65 for receiving the end of the other battery B to be connected on the negative electrode side faces upward.

Next, based on FIG. 8, the manufacturing method of the battery B will be described with the reference numerals of the respective parts described above.
First, as shown in FIG. 8A, the belt-like positive electrode plate 34 and the negative electrode plate 35 are insulated by a separator 36 and wound in a spiral shape to form an electrode group 37 (first step which is an electrode group constituting step). ). Next, as shown in FIG. 8B, the positive electrode current collector 44 is connected to the upper end portion of the positive electrode plate 34 of the electrode group 37, and the negative electrode current collector 38 is resistance to the lower end portion of the negative electrode plate 35 of the electrode group 34. Welding (second step which is a current collector welding step). Then, as shown in FIG. 8C, an electrode group 37 to which the positive electrode current collector 44 and the negative electrode current collector 38 are attached is inserted into the case 31, and the upper opening of the case 31 is secured to ensure airtightness. Bron is applied to the inner surface of 32, and the tongue piece 41 of the negative electrode current collector 38 is joined to the bottom wall 39 of the case 31 by resistance welding (third step).

8D, the sealing plate 33 is attached to the upper opening 32 of the case 31 via the gasket 50, and the sealing plate 33 is resistance-welded to the tongue piece portion 47 of the positive electrode current collector 44. Then, an electrolytic solution is injected from the hole 53 of the sealing plate 33 (fourth step). At this point, the sealing plate 33 is positioned in a state where there is no dimensional variation in the vertical direction of the electrode group 37.
Next, after the end 57 of the vertical wall portion 56 of the sealing plate 33 is folded outward so as to sandwich the gasket 50, a preliminary sealing is performed in which the opening peripheral edge 49 of the bent case 31 is wound downward, and further the sealing plate 33 The vertical sealing portion Z between the vertical wall portion 56 and the opening peripheral edge 49 of the case 31 is caulked to perform the main sealing (fifth step). Finally, the cap 59 is set with the rubber valve body 58 placed on the sealing plate 33, and the flange portion 60 of the cap 59 is resistance-welded to the sealing plate 33 to attach the cap 59 to the sealing plate 33 (first). 6 steps).

Therefore, according to this embodiment, even when the electrode group 37 has a dimensional variation in the height direction, the overlapping portion Z of the vertical wall portion 56 of the outer peripheral edge of the sealing plate 33 and the opening peripheral edge 49 of the case 31 is formed. The position can be adjusted in the vertical direction of the case 31 according to the variation in the height dimension. That is, when the height of the electrode group 37 is smaller than usual, the overlapping portion Z between the vertical wall portion 56 of the sealing plate 33 and the opening peripheral edge 49 of the case 31 is shifted in a direction approaching the bottom wall 39 of the case 31, When the height of the electrode group 37 is larger than usual, the sealing plate 33 is attached to the case 31 in a state in which the dimensional variation of the electrode group 37 is absorbed by simply shifting the overlapping portion Z away from the bottom wall 39 of the case 31. Can be attached.
Therefore, since the sealing plate 33 can be attached to the case 31 in a state where the dimensional variation of the electrode group 37 is absorbed, the degree of freedom of adjustment can be increased. As a result, a tab is not required as in the conventional case, the height dimension can be suppressed, and an increase in internal resistance can be suppressed to the extent that the tab is not required, thereby reducing the number of parts.
Therefore, it is suitable as a small, high-output power source for a driving assist motor for a hybrid vehicle that uses a large number of batteries B in series and has many restrictions on the arrangement space.

  Further, in this embodiment, since the elastic ring part 54 having a convex cross section facing concentrically downward is formed near the outer side of the sealing plate 33, when the sealing plate 33 is caulked against the case 31. The elastic ring portion 54 is elastically deformed and elastically contacts the positive electrode current collector 44. Therefore, dimensional variations can also be suppressed by this elastic force.

Next, a second embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 9, a spring portion 66 is formed on the bottom wall 39 of the case 31 of the battery B of the first embodiment so as to rise toward the inside of the case 31. The case 31 is formed by deep drawing or the like. At the time of molding, the central portion of the bottom 39 is raised to mold the spring portion 66. The negative electrode current collector 38 resistance-welded to the lower end of the negative electrode plate 35 of the electrode group 37 is joined to the upper surface 67 of the spring portion 66 by resistance welding.

According to the second embodiment, even if the height dimension of the electrode group 37 varies, the spring portion 66 of the bottom 39 of the case 31 is effectively used, and the electrode group 37 is made to move by the elastic force of the spring portion 66. By pressing upward, the dimensional variation can be adjusted.
As a result, the sealing plate 33 can be attached to the case 31 in a state in which the dimensional variation of the electrode group 37 is absorbed without using the tab and without increasing the number of parts and the number of manufacturing steps. Of course, the internal resistance can be reduced by eliminating the tab, so that high output can be achieved.

Next, a third embodiment of the present invention will be described with reference to FIG. Since this embodiment has substantially the same configuration as that of the first embodiment, the same portions as those of the first embodiment are denoted by the same reference numerals and described.
Unlike the straight first embodiment, the opening periphery 490 of the case 31 is formed in a stepped shape facing outward. On the other hand, the sealing plate 330 covers the upper surface of the positive electrode current collector 44 and closes the upper opening 320 of the case 31. A work hole 530 is formed in the central portion of the sealing plate 330. Further, an elastic ring portion 540 having a convex cross section concentrically downward is formed near the outer side of the sealing plate 330, and a vertical wall that rises in a direction along the outer wall surface 55 of the case 31 on the outer peripheral edge of the sealing plate 330. A portion 560 is formed.
A gasket 500 having a U-shaped cross section made of nylon or the like is attached to the periphery of the vertical wall portion 560 of the sealing plate 330 so as to wrap it.
The lower edge of the inner peripheral wall 510 of the gasket 500 is suspended so as to cover the inner surface of the vertical wall portion 560 of the sealing plate 330, and the outer peripheral wall 520 of the gasket 500 is suspended so as to cover the outer surface of the vertical wall portion 560 of the sealing plate 330. is doing.

Then, after the vertical wall portion 560 of the sealing plate 330 and the opening peripheral edge 490 of the case 31 are overlapped over the gasket 500 attached to the sealing plate 330, the terminal 570 of the opening peripheral edge 490 of the case 31 is folded inward. The sealing plate 330 is caulked and fixed to the case 31 by winding the vertical wall portion 560 of the sealing plate 330 so as to sandwich the bent gasket 500 on the lower side.
The overlapping portion Z between the vertical wall portion 560 of the sealing plate 330 and the opening peripheral edge 490 of the case 31 is configured as a position adjusting portion with respect to the vertical (vertical) direction of the case 31 of the sealing plate 330.
The insulating material 501 is attached so that the opening peripheral edge 490 of the case 31 covers the portion where the sealing plate 330 is wound.

  A rubber valve body 58 for venting gas is attached to the central portion of the sealing plate 330, and a hat-shaped cross-sectional cap 59 is joined to the sealing plate 330 by the flange portion 60 so as to cover the rubber valve body 58. A cylindrical joining holder 62 having a hole 61 for escaping the cap 59 is attached to the sealing plate 330, and an opening peripheral edge 63 of the joining holder 62 is stepped along the caulking portion 64 of the sealing plate 330. The point that the opening 65 for receiving the end of the negative electrode side of another battery B connected in series is directed upward is the same as in the first embodiment.

  Therefore, also in the third embodiment, even when the electrode group 37 of the battery B has a dimensional variation in the height direction, the vertical wall portion 560 of the outer peripheral edge of the sealing plate 330 and the opening peripheral edge 490 of the case 31 The position of the overlapping portion Z can be adjusted in the vertical direction of the case 31 according to the variation in the height dimension. Therefore, since the sealing plate 330 can be attached to the case 31 in a state where the dimensional variation of the electrode group 37 is absorbed, the degree of freedom of adjustment can be increased. As a result, a tab is not required as in the conventional case, the height dimension can be suppressed, and an increase in internal resistance can be suppressed to the extent that the tab is not required, thereby reducing the number of parts.

  The present invention is not limited to the above embodiment, and can be applied to, for example, a battery used as a drive source for an electric vehicle, and can also be applied to a secondary battery mounted on a fuel cell vehicle together with the fuel cell. it can. Further, the structure of the second embodiment can be applied to the third embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory side view of a hybrid vehicle according to a first embodiment of the present invention. It is side surface explanatory drawing of the high piezoelectric equipment box vicinity of 1st Embodiment of this invention. It is rear surface explanatory drawing of the high piezoelectric equipment box vicinity of 1st Embodiment of this invention. It is a disassembled perspective view of the battery box of 1st Embodiment of this invention. It is sectional drawing of the battery of 1st Embodiment of this invention. It is a disassembled perspective view of the battery of 1st Embodiment of this invention. It is a principal part expanded sectional view of FIG. The manufacturing process of the battery of 1st Embodiment of this invention is shown, 8 (a) is a 1st process, 8 (b) is a 2nd process, 8 (c) is a 3rd process, 8 (d) is a 4th process. , 8 (e) are explanatory views showing a fifth step and 8 (f) is a sixth step. It is a principal part expanded sectional view of the battery of 2nd Embodiment of this invention. It is a principal part expanded sectional view of the battery of 3rd Embodiment of this invention. It is sectional drawing of a prior art.

Explanation of symbols

1 Vehicle 31 Case 32 Upper Opening (Opening)
33 Sealing plate 34 Positive electrode plate 35 Negative electrode plate 36 Separator 37 Electrode group 39 Bottom wall (bottom)
49 Opening peripheral edge 50 Gasket (seal member)
55 Outer wall surface 56 Vertical wall portion 57 Terminal Z Superposition portion

Claims (5)

A battery in which an electrode group in which a strip-like positive electrode plate and a negative electrode plate are insulated by a separator and wound in a spiral shape is housed in a bottomed cylindrical case, and the opening of the case is closed by a sealing plate via a sealing member A vertical wall portion rising in the direction along the outer wall surface of the case is provided at the peripheral edge of the sealing plate, and the vertical wall portion and the peripheral edge of the opening of the case are overlapped to form the peripheral edge of the opening of the case and the sealing plate cell characterized by fixing the said sealing plate to said casing by caulking by bending either one of the vertical wall portion on the lower side after engulfed to the other. 2. The battery according to claim 1, wherein the end of the vertical wall portion of the sealing plate is bent outward and then bent downward to fix the periphery of the opening of the case. 2. The battery according to claim 1, wherein the peripheral edge of the opening of the case is bent inward and then bent downward to fix the vertical wall portion of the sealing plate. The battery according to an item to one of claims 1 to 3, characterized in that it is used as a power source for driving a motor vehicle having a travel drive motor or the traveling drive assist motor. A band-like positive and negative electrode plates accommodating the electrode group wound insulated wound spirally with a separator in a bottomed cylindrical inner case, and the opening of the case was closed by a sealing plate via a sealing member batteries A step of welding the electrode group and the current collector, and a sealing plate provided with a vertical wall portion rising from the opening of the case in a direction along the outer side surface of the case. a step of accommodating the case, further comprising the step of fixing the sealing plate to said casing caulked by bending the lower one of the opening portion and the sealing plate of the case after involving relative to the other A battery manufacturing method.

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